Chrysanthemum indicum Prevents Hydrogen Peroxide-Induced Neurotoxicity by Activating the TrkB/Akt Signaling Pathway in Hippocampal Neuronal Cells

Oxidative stress-mediated neuronal damage is associated with the pathogenesis and development of neurodegenerative diseases. Chrysanthemum indicum has antioxidant properties. However, the neuroprotective effects and the cellular mechanism of C. indicum ethanol extract (CIE) against oxidative damage in hippocampal neuronal cells have not been clearly elucidated. Therefore, this study investigated whether CIE has protective effects against hydrogen peroxide (H2O2)-induced oxidative toxicity in HT22 cells. CIE pretreatment significantly improved neuronal cell viability. Moreover, the formation of intracellular reactive oxygen species and apoptotic bodies, and mitochondrial depolarization were significantly reduced in HT22 cells with H2O2-induced oxidative toxicity. Furthermore, CIE increased the phosphorylation of tropomyosin-related kinase receptor B (TrkB), protein kinase B (Akt), cAMP response element-binding protein, the expression of brain-derived neurotrophic factor, antioxidant enzymes, and the nuclear translocation of nuclear factor erythroid 2-related factor 2 by activating the TrkB/Akt signaling pathway. In contrast, the addition of K252a, a TrkB inhibitor, or MK-2206, an Akt-selective inhibitor, reduced the neuroprotective and antioxidant effects of CIE. Taken together; CIE exhibits neuroprotective and antioxidant effects against oxidative damage. Therefore, it can be a potential agent for treating oxidative stress-related neurodegenerative diseases.